Tire building apparatus



July 25, 1944. H. D. STEVENS TIRE BUILDING APPARA'IUS Filed Aug. 6, 1941 4 Sheets-Sheet 1 am: M

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, TIRE BUILDING APPARA'IUS Filed Aug. 6, 1941 4 Sheets-Shet 2 WCQYMOL HORACE n STEVENS aw 90 9. 85

Jul 25, 1944.

H. STEVENS TIRE BUILDING APPARATUS Filed Aug. 6, 1941 4 Sheets-Sheet 3' HORACE D.5TEVEN5 zif a July 25, 1944. H. D. STEVENS- TIRE BUILDING APPARATUS Filed Aug. 6, 1941 4 sheets sheet 4 Q9 ORWARQSWITCH- REVERSE SWITCH l; l L MAIN MOTOR I Lf] @26 HON A mm X) CYLINDER N957. H4

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:5 lIOb M 4 glllb I W A h floflb flu, w F /|2O 5013403 VALVE m FOR CYLINDER No.52 llGa CL TIMERMOTOR lw :23 HORACE o. STEVENS Patented July 25, 1944 Horace D. Stevens, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron,-

Ohio, a corporation-of Ohio Application August 6, 1941; Serial No. 405,665

This invention relates to tire building apparatus and more especially it relates to stitching mechanism for operating upon the fabric plies of a tire casing after said plies have been applied to a rotatable tire-building form or drum.

The apparatus is designed especially for operative association with tire building drums for the manufacture of large, heavy-duty pneumatic tire casings such as are composed of ten or twelve plies of fabric, and whichinclude at least two r bead cores in each marginal bead. In the manufacture of a tire of the character mentioned by the drum-built method, the bead portions of the tire require to be constructed in substantially the same positions they occupy in the completed tire since heavy double-core beads may not be twisted or deformed during the shaping of the drum-built tire band to conventional tire shape. Accordingly the tire building drums are formed with obliquely undercut side faces upon which the r ter of this invention is employed for working the marginal portions of the fabric plies about the bead cores of a tire being constructed on a drum.

Different fabric plies of a tire are anchored to the bead cores of a tire in a different manner. For example, some plies are turned up around a bead, whereas other plies may be folded under the beads. In such cases the stitching tools that operate upon the fabric may move inwardly over the fabric in the direction of the axis of the tire, or they may move radially outwardly of the tire toward the periphery thereof. Accordingly, one of the chief objects of the invention is to provide fabric-stitching mechanism of the character mentioned that is power operated to move in either direction radially of the tire building drum at relatively slow speed.

The stitching tools also are required to apply some of thefabric plies to the inner circumference of the bead portions of the tire. This operation requires to be effected slowly so that the wrinkles may be worked out of the fabric. The stitching tools are urged toward the work by fluid pressure operated means, with the result that difficulty has been encountered heretofore moving the tools slowly when the fabric is being laid parallel to the direction of'movement of the tools. Accordingly another object of the invention is to provide fluid pressure means for op; erating the stitching tools, including meansfor' stopping the feed of the tool in determinate posif tion for an interval of time, and then permitting the tool to resume its feeding movement. Other} objects will be manifest as the descriptionprof ceeds.

vOf the accompanying drawingst' Figure 1 is a front elevation of apparatus'em-f bodying the invention, and a rotatable tire build-: ing drum upon which tires are built.' L

Figure 2 is a side elevation thereof, on 'a larger scale, in operation upon a tirebeing built upon said drum; y r Figure 3 is a plan view of the apparatus-a part thereof being broken away and in section; f

Figure 4 is a front elevation of the structure showninFigure 2; g 1

Figure 5 is a detail bottom plan view of apluf rality of switch operating cams of the apparatus as viewed from the'line 5-5 of'Figure 4; Figures 6', 7 and 8 arefragmen'tary' sections of a tire building drum with work thereon, and a' fabric stitching tool of the apparatus in operative association with the work in different's'tagesof completion of the latter; and i I Figure 9 is the wiring diagram of theapparatus;

Referring now to Figure 1 ofthe drawings;

there is shown a tire building machine comprise ing a housing In from which projects a horizontal rotatable spindle llupon the free end of which a collapsible tire building form or drum l2 is mounted, there being suitable driving ineansfnot shown) located within the housing Ill for rotat ing said spindle and the drum l2 thereon. The drum I2 is of the type used inthe manufacture of large heavy duty pneumatic tires such as re quire at least two inextensible bead cores ine'ach bead thereof, said drum having oblique, undercut side faces for the reception of the bead cores during the fabrication of a tire. Plies" of tire building fabric are drawn onto the drum, by the rotation thereof, from conveniently positioned stock rolls (not shown), said tire plies being of considerably greater width than the drum toen able the lateral marginal portions of the sues to be folded inwardly onto the undercut lateral faces of the drum. To facilitate the mounting of the fabric plies on the drum, circularsup} ports l3, l3 are positionable in abutting relation to opposite sides of the drum, coaxially there;

with, said supports carrying the marginal portions of the fabric plies until the medial portions of the plies have been rolled down onto the drum, said supports thereafter being moved to their inoperative positions, shown in Figure 1, in spaced relation to the drum. One of the supports I 3 may be slidably mounted for axial movement upon the spindle II, as shown. The other support I3 is swiveled on the upper end of an arm M, the latter being movable relatively of the drum l2 to bring its support 13 into alignment therewith. The fabric plies on the drum 12 are stitched down thereupon by several stitching mechanisms of which but one is shown, that one being known as the back stitcher and constituting the subject matter of the present invention.

The back stitcher is utilized for working the marginal portions of the fabric plies onto the undercut side faces of the drum, and about the bead cores that may be mounted thereon for incorporation in the tire. Said back stitcher comprises a base structure or housing is that is located behind and below the drum I2, the central vertical plane of the base being coincident with the central vertical plane of the drum. The top of the base I6 is formed with parallel, longitudinally extending ways l1, I1, Figure 4, and slidably mounted upon said ways is a carriage !8, the arrangement enabling the carriage to move toward and away from the drum 5 2. Such movement of the carriage is effected by means of a double acting fluid pressure operated cylinder If; that is located within the base I6 near the top thereof, said cylinder comprising a piston rod 20 that projects rearwardly therefrom and at its outer end is connected to a drive plate 25 that is mounted upon the rear face of the carriage 8 and projects below the same to connect with said piston rod.

The top of the carriage I8 is formed with parallel, longitudinally extending ways 24, 24, and slidably mounted upon said ways is a stitcher slide 25, the arrangement being such that the slide 25 is movable toward and away from the drum !2 relatively of the carriage l8 and base 16. For so moving the slide 25, a reversible electric motor 26 is mounted within the carriage t8, the shaft of said motor being coupled to a reduction ear device 21 also carried within said carriage. The driven shaft of the reduction gear device 21 carries a gear 28 that is meshed with a gear 29, the latter being mounted upon one end of a feed screw 30 that is journaled in the front and rear walls of the carriage l8 at the top thereof and in the central plane of the carriage. The feed screw 33 is threaded through a nut 3|, Figure 2, that is secured to the bottom of the slide 25, the arrange ment being such that operation of the motor 26 will move the slide 25 toward or away from the drum l2. Control means presently to be described is provided for the motor 26 whereby the operative proximit of the slide to the drum automatically may be altered for successive phases of a cycle of operation employed in the building of a tire on the drum.

The top of the stitcher slide 25 is formed with ways 33, 33, Figure 2, that extend across said slide, transversely of the ways 25 and ii of the carriage I 8 and base l6 respectively. Slidablymount-- ed upon the ways 33, 33 are two cylinder slides 34, 34 that are positioned on opposite sides of the central plane of the apparatus. Said cylinder slides are adjustable toward and away-from the respective adjusting screws 35 extend through walls of the stitcher slide at the outer ends of the ways 33 and are threaded into the adjacent ends of the respective cylinder slides 34. The arrangement adapts the apparatus for use with tire building drums 12 of different Widths.

Mounted upon the cylinder slides 34 are respective single-acting fluid pressure operated cylinders 31, the axes of said cylinders being hori zontally disposed, and arranged obliquely with relation to the central vertical plane of the apparatus. The horizontal plane of the axes of cylinders 31 is slightly below the axis of the drum [2, as shown in Figure 2., and said cylinder axes converge toward each other at the ends of the cylinders nearest the drum. The cylinders 3'5 are arranged to be charged at the ends thereof nearcentral plane of the apparatus, and to this end est the drum l2, and this end of each cylinder has a piston 38 mounted therein. The cylinders 31 are employed for moving respective stitching tools laterally into operative engagement with the work on the oblique lateral faces of the drum l2, and to this end respective stitcher arms 39 are pivotally mounted at 41! on the cylinder slides 34, at the sides of the respective cylinders 31 that are remote from each other. Each cylinder 3'! is formed with a slot 4! Figure 3, therein rearwardly of its piston 38, and each stitcher arm is formed, at its pivot 48, with a laterally projecting finger 42 that extends through the slot 4| cf the adjacent cylinder, the free end of said finger being engaged by the piston 38 of the cylinder. Each stitcher arm 39 has a rearward extension 39a beyond its pivot 40 and connected to the free end of said extension is one end of a tension spring 43, the latter extending across the top of the a jaoent cylinder 31 and having its other end connected to an upwardly projecting lug 44 formed on said cylinder. The arrangement is such that the springs 43 normally hold the fingers 42 of the stitcher arms 39 against the rear ends of the respective pistons 38 at all times, thus urging the free forward ends of the stitcher arms away from the drum l2.

The forward end of each stitcher arm 38 carries a short lever 4'6 that is journaled at its middle therein on a vertical axis, the end of each lever 46 that is nearest the drum l2 having a rotatable stitching disc 41 swiveled thereon on a horizontal axis. Pivotally connected to the opposite end of each lever 46 is a clevis 48 connected by a rigid link 49 with a swivel 50 that is pivotally mounted upon the cylinder slide 34. The link 49 has threaded connection with the clevis 43 and swivel 5B, the arrangement being such as to enable the lever 46 to be adjusted angularly with relation to the stitcher arm 39. The link 49 is parallel to the stitcher arm 39, and the distance between the pivotal connections at the ends of each is substantially equal so that the stitcher arm and link constitute a parallel motion device for moving the stitching tool 41 from and toward the drum I2, as indicated in full lines and in broken lines in Figure 3, while maintaining said tool in a determinate angular position.

The stitching tools 41 are moved radially with relation to the drum 42 by the cylinder l9 and motor 26 as hereinafter will be more fully explained, and are moved laterally toward the drum by the pistons 38 of cylinders 31. The cylinders 31 thus provide the pressure for stitching down the plies of tire fabric on the lateral faces of the drum. Some of the over-bead fabric plies of a tire require to be folded onto the inner circumferential surfaces of the tire, that is, onto the inner cirl'cumferencesof 'the bead portions thereof, and this operationalso is performed by the'stitching tools 41:; WHowever; this operation initially produces -:nunierous'folds or wrinkles in the marginsof the fabric, which'folds and vwrinkles require to be worked, out by the tools 41 to produce an acceptableztire. "Accordingly said tools must be moved laterally across the inner faces of the beads at a slower rate than they would move if impelled normally by the cylinders 31. To this end means is provided for halting the movement of the vtools transversely of the inner circumference of the :beads for a sufficient interval of time to enable the folds or Wrinkles in the fabric to be smoothed out. =,=Said means: comprises fluid pressure operated :cylinders 52 acting in opposition to the respective cylinders 31. Each cylinder 52 is coaxially arranged with relation to its companion cylinder 31, at the rear of the latter, the cylinder head at'the front end of each cylinder 52 being provided with an axially apertured, forwardly projecting formation 53 that is threaded through the rear cylinderi'head of the cylinder 31, thus to support the cylinder 52 upon the latter. The cylinders 52 are :single acting and are arranged to be charged-at their rear ends. Each cylinder 52 comprises a piston 54 having a piston rod 55 that extends through the axial aperture in the formation-53 .and into the rear end of the cylinder 31 where it constitutes a stop for the finger 42 of stitcher arm 39 under certain conditions of operation.

The cylinders 52 are utilized during the final stitching operation upon a tire to fold the outer-- most over-bead plies onto theinner circumference of the tire beads, as shown in Figure 8. When the apparatus starts'to perform the operation shown in Figure 8, the cylinder I9 is charged to move the carriage"! toward the drum l2 and cylinders 31 are charged to move the stitchingtools- 41 into engagement with the tire on the drum, the tools engaging: the sides of the tire above the beads as shown in full lines in Figures 3 and 8. The cyl- 'inders 52 are charged concurrently with the charging of cylinders 31, with the result that piston rods 55 are projected into the rear ends of cylinders 31, as is clearly shown in Figure 3. The.

.motor 26 then starts rotating in the direction vthatfeeds the slide 25 toward the drum with the result that the tools 41 are fed toward the inner circumference of the tire being built on the drum, the cylinders 31 at the same time urging said tools laterally against said tire. As the tools 41 reach the ,inner circumference of the tire they move laterally across the beads of the tire, and it is at this time that the'fingers 42 of the stitcher arm 39 encounter the piston rods 55 of the cyl- 'in ders 52, with the result that the lateral movement of the-stitching tools is halted. At this time the tools 41 are about half way across thetire beads, as is indicated by the broken line position ofthe tool 41 in Figure 8. While the tools.41 are in thislposition, the cylinder l 9 is bumped, that is, it is reversed so as to move the carriage l8 crearwardly and almost immediately again isre- Iversed to move it forwardly to original position. Such movement of the carriage draws the tools 41 radially outwardly against the inner' circumference of the tire beads and causes the tools to work out any folds or wrinkles in the fabric at the marginal regions thereof, the drum l2 making several revolutions during'the bumping operation. Then the cylinders 52 automatically are exhausted enabling the pistons 38 of the cylinders'31 to swing the arms 39 laterally toward the drum and causing the tools 41 to complete *their movement across the inner circumference of the; tirebeads to stitchthe margins of the'tire building material thereon." The operation of .cylinders 31 and I9 and? the motorv 26 is then reversed torestore the apparatus'to inoperative position; y

Referring now to Figures 6 to 8, astitching tool 41 is shown in several of the positions it occupies during the building of a large size tire,- specifically, a tire having I0 plies of tire building-fabric. vSaid plies initially may be applied to the drum singly, but the tools operate upon a plurality of;;the plies at a time. Thus inFigure 6 is shown the step of stitching down plies l to4; in Figure '1. is shown the step of back-stitching plies 1 and 8 over. the outermost of a pair of bead cores; and in Figure 8 is shown the step of stitching down plies 9 and I0 together with chaferstrip and sidewall of the tire. The, apparatus also. performs intermediate operations. (not shown) as will be understood by those skilled in the art, illustration thereof being omitted to. avoid duplication. vA comparison of Figures 6, 7, and 8 will show that the tools 41 operate uponthe tire in a radially inward and in radially outward directions, and that points wherethe tools engage the tire and where they withdraw fromthe tireldiffer according to which operation they are performing on thetire. f I Q For causing the tools 41 initially to engage the 'work at different determinate positions 'for the various operations, the motor 26 is employed to move the slide 25 relatively of the carriage 18; to

set up theapparatus for the succeedin operation, such movement of the slide being effected 'tire' a determined distance by suitable control means that in some operations stops and reverses the drive of the motor 26 after the tools have been moved radially of the tire the proper distance to "achieve a particular stitching operation. The circuit of the motor 26 comprises a limit switch 58 mounted upon one sideofthe'base "structure I 6, and a-limit switch' 59 mounted upon the opposite side of the carriage 18'. The operating leverof switch 58 extends into'the path of'a cam 60 carried upon the side of carriage I8, and the operating lever of limit switch 55 extends into the path of acam 6| carried by the slide 25. The arrangement is such that when the rear end *0: cylinder I9 is charged to move the carriage l8 forwardly relatively of base structure I6; cam 60 operates switch 58' to effect the "driving of motor 26 in the proper direction to perform the desired operation on the work. As 'soon as this operation is performed the motor in some cases,

the slide 25 reaches its rearmost position, relatively of thecarriage I I 8; the cam 6| operates switch'59 to reverse the drive of motor 26 to move the "slide 25' forwardly a determinate distance to set up the apparatus for the succeeding operation.'

Other switches'in the motor-control circuit are -carried by tl'ie carriage l8 and to operate the same therelative' movement between said carriage and 'the slide 25' is utilized; To this 'end a supporting bracket 63 is mounted upon one side -of the carri'age l8 and projects laterally therefrom. similar bracket 64'is similarly mountedon the other side of said carriage. Garried by the-bracket 63 are five switches designated 66, 61, 68, 69, and respectively, said switches having respective upwardly extending levers by means of which they are operated. For operating said switches a cam plate II is secured to the under side of slide 25, above said switches, and adjustabl'y mounted on said cam plate are cams I2, 13, 14, 15, and I6 that are in fore-andaft alignment with the operating levers of the respective switches'66 to 10. Switches 66 to 69 are stop switches for the setting up of the apparatus, and they stop the motor 26 after it has been energizedby the switch 59 to move the slide 25 forwardly. By the proper positioning of the cams 12 to 15 the slide is'stopped at a plurality of, different positions so that the tools 41 properly will engage the work at the beginning of the succeeding stitching operation. More specifically, switch 66 is a normally closed safety switch that limits the forwardmovement of the carriage I8 in case of over-run. It does not open during normal operation of the apparatus. Switch 6'! is a stop switchthat sets up the apparatus for operation upon the first four tire plies,

which operation is shown in Figure 6, and upon the second four tire plies. switch that sets up the apparatus for stitching down the first tire bead, in which operation the .tools 41 are moved radially outwardly of the drum I2. Switch 69 is a stop switch for setting up the apparatus for the turning up of the third and fourth fabric plies about the first tire bead, and for turning up the seventh and eighth fabric plies upon the second tire bead, the latter operation being shown in Figure 7, both operations requiring that the tools 41 move radially outwardly with relation to the drum I2. Switch 10 is a reversing switch .to reverse motor-26 and thereby to enable the plies 5 and 6 to be turned under the first tire bead, after plies I and 8 have been turned switches 'and the switch 10, .be operated each time the slide is moved forwardly, and the sequence of operation does not require the switches to be operated in the succession shown. To this end control means is provided that automatically operatively connects the switches 61 to I0 with the motor circuit in determinate sequence to the end that each switch will function to stop the motor 26, orreverse-thesame, when operated by its companion cam only during the particular phase of operation for'which the switch'was designed. 1 r

The arrangement of said control means will best be understood by reference to Fig. 9 of the drawings. Shown therein is a ratchet relay I02 that is energized by the actuation of limit switch 59 upon each return of theslide 25. Relay I02 controls the closing of a plurality of switches, of which only one switch I02a is-shown, it being understood that said switches are operated in succession, a succeding switch being closed each time the relay is energized, and the previously closed switch being opened. Switch I02a, when closed, energizes relay I04, and operation of the Switch 60 is a stop latter. closes normally open switches I04a'Jand I04b. Closing of switch I04a energizes set up switch I24, it being noted that the'closing of limitswitch '59 also energized relay I03 and the latter has closed switches I03a' and I03b. Set-up switch I24 is adjustable so that the circuit may be shifted to any of the limit switches in the setup circuit, namely, switches 61, 68, 69 and I0. It will be understood that the other switches "of ratchet relay I 02, like I02a, control respective relays such as I04, and each of the latter controls the operation of a set-up switch (not shown) similar to set-up switch I24, all of the said set-up switches being connected in parallel with each other. The arrangement enables setup limit switches 61, 68, 69 and 10 to be brought into operation in the desired sequence for the manufacture of tires of various ply arrangements. The bracket 64 on the opposite side of the carriage I8 carries seven electrical switches designated 18, I9, 80, 8|, 82, 83, and 84 respectively, of which switches 18 to BI inclusive are in the motor control circuit, the operating levers of said cams are aligned with the operating levers of the respective switches 18 to 84, and operate the latter during the intervals that the tools 41 are engaged with the work. Thus it Will be understood that switches "I8 to 84 are so positioned that they operate after the time that respective switches 61 to 10 are operated. I

The switches 78 to 8| function to stop the drive of the motor 26 in the direction that it is rotating and cause it to rotate in reverse direction. More specifically the switch -'I8 is a stop switch for the operation of switching down plies 9 and I0 under the outer beads, and for the bump. Switch I9 is a stop switch for the operation of stitching down the first four fabric plies, as shown in Figure 6, the switch stopping and reversing the motor when the tools 41 are in the position shown in full lines in said figure. Switch 80 stops and reverses the motor at the completion of the operation of stitching down the second four plies of tire fabric. Switch 8| stops and. reverses the motor as the margins of plies 5 and 6 are folded onto the inner circumference of the beads of the tire. Switch 82 is operated at the completion of the back-stitching of the first or inner tire bead. Switch 83 operates at the completion of the back-stitching of the thirdand fourth fabric plies onto the inner tire bead. Switch 84 "operates at the completion of the back-stitching of the seventh and eighth fabric plies onto the second or outer bead, which operation'is shown in Figure 7. The switches I8 to 84 are mounted in the circuit of the motor 26 in a manner similar to switches 61 to 10, there being other control serve another purpose presently tobe'explained. For "cutting the switches- 'I8 -to' 84 into the circuit selectively desired-sequence, aselector switch I 25 is provided, ,the 's'ame' being brought into operation bythe closing of switch I04b aforementioned.- Selectorswitch I25' is adjustable so "that any one of seven relay circuits may be energized; It said: circuits including relays I05, I06, I01,"-I08, -I09, I-IIl'a'nd 'II'I; lilach of said relays when energized servesto 'close one'or more normally open switches; of which switch I05a is invseries with switch I9, switch I06a is in series with switch 80, switch I'la isin series With switch 8|, switch 19b is in series withswitch 82, switch I I0!) isin series with switch 83, switch I b is in: series with switch 84,and switch IBM is in series with-switchIB. Switches I9 to 84 together with the aforementioned switches in series therewith are in the circuit of a relay II8, the latter arranged to operate normally closed switches II8a, I-I8b, and'normally open switches H80, 1 I8d. Switch 108a is inseries With switch "in the circuit of a relay vI19, the function'of which presently will be explained. Switches I09a,- II 0a, and la are arranged in parallel in the circuit of a 'relay -II2, which relay controls a normally closed switch I I2a in-the circuit ofa relay II 6, and a normally open switch H21: in the circuit of relay 1. 1 All ofsaid limit switches 78 to 84 have connection-with one side of the-main power line through switch IIIIb controlled by starter relay II", the circuit of which includes a manually operable starter button I00. The holding circuit of relay IOI includes a switch IOIaoperated by said relay, and the limit switch 59.

The fluid pressure operated cylinders I9, 31, and 52 require to beoperated at determinate intervals with relation to the operation of the motor 26, and in the present invention such'operation of the cylinders is effected automatically by means of solenoid-operated valves H5, H3 and I20 respectively, which valves are operated by various switches in the electrical control of the apparatus. The valve II5 that operates cylinder I9 is electrically operated by the switches I8 to 84 to. charge the front end of the'cylinder and evacuate the rear end thereof for the purpose of moving the carriage I8'rearward1y at the conclusion of each stitching operation; This valve control also includes the switch IOIb closed by the manually operated switch I0 by means of which the rear end of the cylinder is charged to move the carriage I8 forwardly at the beginning of each operation. The cylinders 31 are concurrently charged by means of a solenoid valve II3 that is operated by the switch 58, closing of the latter energizing relay H4 which closes switch 4b in the circuit of solenoid'valve I I3, and also closes switch Illa in the circuit of relays II6, and 1. This valve H3 is reversed or discharged by the opening of switch II4b when the relay H4 is de-energized by the opening of switch I I 8a of relay II8 when the latter is energized by the closing of respective switches 19 to 84. The cylinders 52 are charged and discharged by means of a solenoid valve I20 that is controlled by atiming device comprising a timer motor .I2I that operates normally open switches I2Ia, I2Id, and normally closed switches I2Ib and I2Ic, the switch I2Ib being in series with switch I08b .in the circuit of said solenoid valve I20. Said timing device is set in operation by the closing of limit switch 18 whereby relay H9 isenergized ,to close switch II'Ba-in the circuit operation.

of saidtimer motor I2I.' The latterhas a holding circuit in 1 which switch I2-Im is located. Switch I2Ic is in the circuit of the solenoidyalve II5-and switch I2Id is in the-circuit of the re- Thefpower circuit-of the main motor'26 includes the usual manually operated master switch I30, an automatically operated switch I22a for so connecting the motor as 'to drive the slide" 25-forwardly toward the work, and an'automati'cally operated switch I23a for reversing the drive of the motor. Switch I22a is operated by relay I22, the circuit of which-includes switches 1031) and IIfia arranged in parallel and the limit switch 68.4 Reverse switch I230, is operated by relay I23, the circuit of which includes theswitch Il'Iaof relay I".

A typical cycle of operation is as follows: At thebeginning of the operation of building a tire on the drum I2, the slide 25 isin a forward position'relatively of the carriage l8, as shown in fulllines in Figure 2, its position-having been determinedby operation of the set-up switch 81' at the conclusion of the preceding cycle of The apparatus of the invention is employed after the first four plies of fabric have been mounted on the drum and folded over the rounded lateral margins thereof. To start the cycle of'operation requires the operator merely 'to actuate the manually operable switch I00 that effiects the charging of the rear end of cylinder I9, through the agency-of solenoid valve II5 all subsequent operations being automatically effected. Charging of the rear end of cylinder I9 moves the carriage I8 forwardly toward'the drum I2, from the broken line position of Figure 2 to the full line position therein, and at substantially the limit of such forward movementof the carriage the cam 60 operates switch 58. This results in the charging of cylinders 31 through the agency of 'solenoid valve II3, to move the stitching tools 41 laterally into engagement with the fabric plies on the sloping sides of the drum, and also starts the drive of' the motor 26, by energizing relay II6 to close-switch 601, in the circuit of relay I22 controlling motor-switch I22a, tomove the slide 25 toward the drum, relatively of the carriage 18. The operation of the tools 41 on the workisshownin Figure 6, the tools engaging thework atthe position shown in broken lines,-the movementof the slide 25 carrying the tools to the toolposition shown in full lines. Forward position of the tools 41 is determined by the stop switch-19. When the latter is operated by thecam 81 on the forwardly moving slide 25, it first energizes relay II8 which opens switch I I8a and thereby de-energ'izes relay II4, with resulting de -en'ergi'zation of solenoid valve II3-to effect discharge of cylinders and thereby permits springs 43 to swing the tools 41 laterally away from the work.- It also reverses the direction of drive of motor 26 by effecting the opening of switch 6 and the closing of switch II'Ia, so that the mo tor' starts to move the slide 25 rearwardly-relatively of carriage I8, and concurrently it operates to de-energ ize the solenoid valve I I5 that controlsv the cylinder- I9,

to charge the front end of the latter while discharging the rear end thereof, whereby the carriage I8 is moved rearwa'rdly relatively of the base I6, back to theposition'shown in broken lines in Figure 2. As the rearwardly moving slide 25 reaches itsrearmost position relatively of the carriage I8,,cam 6I. on the slidejengages and operates switch 59 to reverse the drive of motor 26, and the latter again feeds theslide forwardly relatively of carriage I8. Such movement of the slide continues until stopped by the engagement of-the cam 14 with the switch 68, the apparatus then being set up for the stitching .down of tire beads that are next to be mounted upon the drum. This completes the cycle of operation for the application of the first four fabric plies to the drum. 7 A

The cycle of operation differs somewhat when the switching operation requires tools 4!- to move outwardly with relation tothe drum I2. Such a stitching operation is shown in Figure '7 wherein the seventh and eighth fabric plies are stitched onto the outside of the second or outermost tire beads, the stitching tools engaging the work first at the position shown in broken lines and progressing outwardly therefrom beyond the tool position shown in full lines in said figure. The apparatus is set up for this operation by the actu-. ation of switch 69 at the conclusion ,of the prior operation. At the beginning of this operation, when the; manually controlled starting switch lilil is; actuated to charge the rear end of cylinder l9, thecarriage [8 moves forwardly and operatesswitch 58 in the usual manner. This results in the charging of cylinders 31 to move the tools =41 against the work, and starts the drive of motor 26. The latter, however, by reason of the set up, is caused to rotate in the direction that moves the slide 25 rearwardly and thus moves the tools 41 radially outwardly of the work, as shown in Figure '7. This condition obtains until cam 92 engages and actuates switch 84 with the result that cylinders 3'1 are dischargedto move the tools 41 away from the work and the front end of cylinder [9 is charged tomove the carriage I8 to its retracted position. Motor 26, however, continues its driving to move the-slide 25 rearwardly, relatively of carriage l8, until cam 6| operates switch 59, with the result that the motor then reverses its drive and feeds the slide forwardly until stopped .by the proper set up switch for the succeeding operation.

From the foregoing it will be apparent that the apparatus is substantially entirely automatic in its operation, and performs a plurality of different operations requiring different initial positioning of the stitching tools. It also enables the tools to be moved radially of the work while engaged therewith at a relatively slow speed, yet to be moved rapidly from and toward the work while :out of engagement therewith. The presence-of the cylinders 52 enables the tools l! to stop and dwell at the determinate position upon the work,,not withstanding the pressure of the cylinders 31 that urge the tools toward movement relatively of the work. The invention reduces-the time requiredfor the manufacture of pneumatic tire casings, and achieves the other objects set forth in. theforegoing statement of jec s parting from the spiritof the invention, or the scope thereof as defined by the appended claims.

.What is claimedis: 1. In tire building apparatus, a stitching mechanism comprising a pair of stitching tools adapted to operate upon the bead portions of a tire structure on the undercut lateral faces of a rotatable annular form, fluid pressure operated means for moving said tools laterally with relation to the form into and out of engagement with said'tire structure, electrically driven means for moving saidtools radially with relation to the odification may be resorted to without de-.

form whileengaged, with a, tire on said form, a carriage supporting said, stitching tools, fluid pressure operated .meansgand; electrically driven means, said carriage movable towardand away from the form; and, means controlled by movement ofthe carriage toward the form for effecting concurrent actuation of said fluid pressure means andsaid electrically, driven means.

2. In tire building apparatus, a stitching mechanism comprising .a pair of stitching tools adapted to operate upon a tire structure on a rotatable annular form, fluid pressure operated means for moving said tools radially of the form toand from determinate positions at the sides of the form, fluid pressure. operated means, for urging said toolslaterally againstthe work On the sides of the form,-an d electrically driven means for moving said tools radially of the form after being engaged with the work thereon. x 3 Intire building apparatus, a stitching mechanismcomprising a pair of stitching tools adapted to operate upon a tire structure on a rotatable annularform, fluid pressure operated means for moving said tools a determinate distance toward said form, means for temporarily interrupting said movement of the tools at a determinate position with relation to the form and intermediate the extremities of said movement, and means withdrawing said interrupting means ,automatically after a determinate time interval.

4. In a tire building apparatus, a stitching mechanism comprising a pair of stitching tools adapted to operate upon a tire structure on a rotatable annular form, fluid pressure operated means for moving said tools toward said form, means arranged in opposition to said fluid pressure operated means for temporarily impeding the movement 'of the tools under the impetus thereof, and timing apparatus for effecting withdrawal of said impeding means from impeding position after a determinate time interval.

5. A combination as defined in claim 4 wherein the impeding means comprises a fluid pressure operated cylinder.

6. In tire building apparatus, a stitching mech anism comprising a pair of stitching tools adapted to operate against a tire structure on a rotatable annular form, fluid pressure operated means for moving said tools laterally from and toward said form, a slide carrying said fluid pressure operated means, a carriage supporting said slide, a base structure supporting said carriage, means for moving said carriage relatively of the base structure toward and from said form to carry the tools to work-engaging position, and means for moving the slide relatively of the carriage in the same directions as the movements of the latter to move the tools operatively over the work on the form. 7. A combination 'as defined in claim 6 wherein the means 'for moving the carriage relatively of the base structure is a fluid pressure cylinder, and the means for moving the slide relatively of the carriage is a motor driven feed screw.

8. In tire building apparatus, a stitching mechanism comprising a stitching tool adapted to operate against a tire structure on a rotatable annular tire building form, a slide upon which said tool is mounted, a carriage supporting said slide, a base structure supporting said carriage, fluid press-ureoperated means for moving the carriage toward and from the said form and relativelyyof said -base structure, an electric motor for moving said slide toward and from the said form and relatively of the carriage, and switch means in the motor circuit for causing the motor to position the slide at difierent inoperative positions relatively of the carriage after successive tire stitching operations.

9. A combination as defined in claim 8 wherein the switch means comprises a plurality of electrical switches mounted on the carriage and a plurality of cams on the slide adapted to operate respective switches by reason of relative movement between slide and carriage.

10. A combination as defined in claim 8 including switch means in the motor circuit for effecting the driving of the motor after the carriage has moved a determinate distance toward the tire building form.

11. In tire building apparatus, a stitching mechanism comprising a. stitching tool adapted to operate against a tire structure on a rotatable annular tire building form, a slide upon which said tool is mounted, a carriage supporting said slide, a base structure supporting said carriage, means for moving the carriage from and toward said form and relatively of said base structure, a reversible electric motor for moving the slide from and toward said form relatively of said carriage, and a plurality of reversing switches in the motor circuit operated by relative movement between the carriage and slide for retracting the slide after the stitching tool has moved a determinate distance while engaged with the tire, said reversing switches operating at difierent relative positions of the slide in successive cycles of operation.

12. A combination as defined in claim 11 including a reversing switch in the motor circuit operated by relative movement between the slide and carriage for automatically again moving the slide toward the form after said slide has reached the limit of its rearward movement.

HORACE D. STEVENS. 

